Installing a shower base in the basement

Asked Jan 25, 2006, 09:31 AM
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17 Answers

We bought a home that already had a sewage pump installed in the basement with three drains already installed in the concrete floor that leads to this pump's tank. One was for a toilet (which is covered), another is for a sink (which at present is in use) and the third is a drain pipe (rubber cover) about 4.0 inches in diameter and sticks 3 inches out of the concrete floor. It is the last one that we want to use as the drain to a shower.

The third pipe leads directly into the sewage pump tank that is located within the basement floor.

What is the best way of installing a self made shower base for the 4.0 inch drain? Because a trap is needed, how high must the base be built off the basement floor? I would like the shower base to be as close as possible to the floor but I perfer not to dig up the concrete floor.

"What is the best way of installing a self made shower base for the 4.0 inch drain? Because a trap is needed, how high must the base be built off the basement floor? I would like the shower base to be as close as possible to the floor but I perfer not to dig up the concrete floor."

Well Thad,
I hate to break this to you but there is no way that you're going to a 2" trap that installs on a 2" horizontal drain line to connect to a 4" vertical raiser. Your best bet, since the shower must be vented, is to break up the floor and connect the shower to the lavatory drain line so it will be wet vented. As for the 4" stub-up, I can think of no reson to bring a 4" pipe up to grade unless it's toy pick up a toilet. It's too big to pick up anything else and the fact t6hat it'sgot a vertical raiser prevents anything but a toilet to be installed on it. I would pick up a set if inside cutters, cut it below the floor line , cap it and cement over it. Good luck, Tom

"I hate to break this to you but there is no way that you're going to a 2" trap that installs on a 2" horizontal drain line to connect to a 4" vertical raiser. Your best bet, since the shower must be vented"

Thank you for your response but I do not understand want you wrote.

First, in the already installed sealed, sewage pump (which has a tank aready installed under the concrete floor) there is an existing pipe coming out of the unit that leads to the roof. What I am saying is that the whole system is aready vented. The whole sewage pump system already has three possible places to attach drains. One of these is in use now and the other two are capped. Are you saying that if I make one of the capped drains a shower drain, that I must somehow vent this separately?

Second, I don't think I made it clear as to the demensions of the capped pipe coming out of the concrete floor. The head of the pipe is 3.5 inches (not 4" like I said before) and as I look down the drain with a flashlight the actual pipe diameter is 2". This pipe sticks out of the floor 3.5" high. I know that this pipe runs down to the sewage pump's tank because when I run water down the pipe I can hear it splashing into the tank.

I do not know what you mean by a "4" vertical riser". As I said before the pipe diameter coming out of the concrete is 2". This pipe has a head on it that is 3.5" wide so that a 2" trap could be fit into it.

"I do not know what you mean by a "4" vertical riser". As I said before the pipe diameter coming out of the concrete is 2". This pipe has a head on it that is 3.5" wide so that a 2" trap could be fit into it.?"

Thad, You described a 4" vertical pipe, (raiser) comming out of the floor. You then asked,"What is the best way of installing a self made shower base for the 4.0 inch drain?"

"the third is a drain pipe (rubber cover) about 4.0 inches in diameter and sticks 3 inches out of the concrete floor. It is the last one that we want to use as the drain to a shower.
The third pipe leads directly into the sewage pump tank that is located within the basement floor.
What is the best way of installing a self made shower base for the 4.0 inch drain?"
You went on to say, " As I said before the pipe diameter coming out of the concrete is 2". This pipe has a head on it that is 3.5" wide so that a 2" trap could be fit into it."

Go back as read what you posted earlier, the third is a drain pipe (rubber cover) about 4.0 inches in diameter and sticks 3 inches out of the concrete floor. It is the last one that we want to use as the drain to a shower."

Now that you have me completely confused would you care to go back and state your question again, bearing in mind that you can not connect a showers "P" trap to a pipe that's vertical
Yours in puzzlement, Tom

Now that you have me completely confused would you care to go back and state your question again, bearing in mind that you can not connect a showers "P" trap to a pipe thats vertical

Unless, of course, you platform the shower such that the vertical pipe is actually outside the shower, connect the shower trap from underneath the platform to the riser with a short piece of horizontal pipe, and cap off the riser with an AAV (a.k.a. cheater vent) - if it's legal in your area. Am I correct, Tom?

Moshie,
First it was a 4" pipe comimg out of the cement. Then it was 3 1/2" and now it's a 2" pipe with a 3 1/2" increaser
Moshie, You're correct but that's not how it was phrased, He said, "As I said before the pipe diameter coming out of the concrete is 2". This pipe has a head on it that is 3.5" wide so that a 2" trap could be fit into it."
Perhaps I'm reading him wrong, but when I run into a job that has as many contradictions in it as his question I get a little nervous. In order for us to give a clear answer we must have clear and concise questions. If we have to guess at the problem and drag the specifics out of the asker like pulling a abscessed tooth, ( we are jusr going through a toilet question like that) then
That just makes our job that much more difficult. Cheers, Tom

If we have to guess at the problem and drag the specifics out of the asker like pulling a abscessed tooth, ( we are jusr going through a toilet question like that) then that just makes our job that much more difficult.

You bet! (By the way, did you see my latest responses to the toilet question?) I was just saying that it theoretically CAN be done (using an AAV), just quite different from the way he wanted to do it. ;)

I wish you would had done this,(posted photos), to began with. The pipe that you wish to connect is the female hub of a piece of service weight( SV) 2" cast iron.
Moshie had the right idea. What you can do is lead in a 2" PVC drainage tee on a short piece of PVC pipe. On top of the tee you will install a AAV,(air admittence valve on a piece of PVC the raises it up over the shower floor drain . You are now free to figure out the elevation of the platform to accommodate the trap. Make sure the shower drain is within 5' of the trap and before you start make sure that you have enough head room with the shower enclosure setting on the platform. My apologies for all the confusion and if we can be of further help feel free to call on us. Regards, Tom

I did not realize that AAV was needed because as you can see by the picture, the tank of the sewage system is vented. I would have thought that that venting was enough to allow the water to flow down the shower drain with no problems.

I do have some questions, just to make it clear to me as to what I am to do...

1. The 2" SV pipe will have to be built into the wall or behind the bathroom wall ... correct? I am thinking of making this wall a 2X6 thick wall to take care of all the pipes that it will contain.

2. One of my thoughts was to cut into the concrete around the cast iron pipe and dig down far enough so that the trap could be installed partially, or completely below the level of the floor. This would involve cutting the cast iron pipe and then connecting the trap and recementing around it. Does this sound feasible? or is it more trouble than it is worth in your opinion? By the way, I could put in a base that was a foot high and still have 6' and a half feet for the shower.

3. The top of the female cast iron pipe is 2.25" off the concrete floor (I remeasured this), the T will add another 2", and the trap will add (about) 3", so the total height for the base will be about 8" or so. Does that sound reasonable?

4. I am making an assumption that when the AAV is added that no smell will come from the drainage system if all the seams are watertight, correct?

5. I plan to move the in use sink (not shown in the pictures) so that it will be on the opposite side of the bathroom in a work room. The work room will then have a sink. Would it be better to connect the drain to this sink to the AAVed shower drain (in some way) or just run a pvc pipe (this would be about an 8' run of pipe) from the original location of the now existing drain?

6. I have two pcv pipes (hot and cold water) that already run to the existing sink( sink to be moved to the workroom). With the new bathroom, these pipes would supply, the toilet, the shower, a vanity, and a workroom sink. Do you think that this is too much for just two (half inch) water pipes to handle?

About the pictures, I was getting pretty frustrated trying to explain in words what I wanted to do, so I had to learn how to put pictures on the web (I never did it before). Would it be OK if I roughed in the pipes so you could see if they are done correctly and you could tell me if I am doing it properly?

I still have a lot of questions as to how the base will be made. I think it will involve pressure treated wood, cement board and some type of filler to make the slope on the bottom of the shower, but I will wait until later for these.

"I did not realize that AAV was needed because as you can see by the picture, the tank of the sewage system is vented. I would have thought that that venting was enough to allow the water to flow down the shower drain with no problems."
Every fixture that's trapped must have a vent. The shower vent draws air in to break the suction created by the draining water. If you used the holding tank vent, which is a rwo way vent as opposed to a regular vent that is only one way would choke the discharge and set yourself up for blockages. To attempt to vent out the tank you would impede the discharge in two ways. First, the discharge would be slowed down because the trap seal would not alow the suction to be relieved and you get a double whammy when the discharge hits the holding tank because now you're forcing the discharge to push air all the way out the roof vent. The shower MUST be vented.

1. "The 2" SV pipe will have to be built into the wall or behind the bathroom wall... correct? I am thinking of making this wall a 2X6 thick wall to take care of all the pipes that it will contain."
If you wish to platform the shower, yes. I would leave a access plate so the AAV can be serviced if need be.

2. "One of my thoughts was to cut into the concrete around the cast iron pipe and dig down far enough so that the trap could be installed partially, or completely below the level of the floor. This would involve cutting the cast iron pipe and then connecting the trap and recementing around it. Does this sound feasible? Or is it more trouble than it is worth in your opinion? By the way, I could put in a base that was a foot high and still have 6' and a half feet for the shower."
Platforming the shower would be the easiest but cutting the cement and installing the trap underground would be the most correct. If you did that you would still have to raise a vent back up the past the wall. With a wall in place could you run the vent to the attic where you could revent back into a existing vent or take it out the roof?

3. "The top of the female cast iron pipe is 2.25" off the concrete floor (I remeasured this), the T will add another 2", and the trap will add (about) 3", so the total height for the base will be about 8" or so. Does that sound reasonable?"
Since the trap will come off the branch of the tee all you need to be concerned with is that the bell of the trap clears the ground. There will be a short raiser off the trap to connect into the shower drain that will raise it a little more. 8 or a few inches under sounds about right.

4. "I am making an assumption that when the AAV is added that no smell will come from the drainage system if all the seams are watertight, correct?"

Correct. The AAV only breathes in.

5. "I plan to move the in use sink (not shown in the pictures) so that it will be on the opposite side of the bathroom in a work room. The work room will then have a sink. Would it be better to connect the drain to this sink to the AAVed shower drain (in some way) or just run a pvc pipe (this would be about an 8' run of pipe) from the original location of the now existing drain?"

Ahh! First I've heard about adding sink. If you platform the shower and plan to tie the sink drain to the shower drain you might as well raise the entire basement floor. Otherwise you'd have the sink drain running on top of the cement.
"this would be about an 8' run of pipe) from the original location of the now existing drain"
What existing drain?? You have a vented lavatory in use at the present time?
Why not break up the cement and tie all the drain lines to the existing lavatory drain and let it wet vent the others?

6. "I have two pcv pipes (hot and cold water) that already run to the existing sink(to be moved to the workroom). With the new bathroom, these pipes would supply, the toilet, the shower, a vanity, and a workroom sink. Do you think that this is too much for just two (half inch) water pipes to handle?

6. "I have two pcv pipes (hot and cold water) that already run to the existing sink(to be moved to the workroom). With the new bathroom, these pipes would supply, the toilet, the shower, a vanity, and a workroom sink. Do you think that this is too much for just two (half inch) water pipes to handle?"

I think the 1/2" will work just fine. If you're concerned install Anti-Skald shower valve.

" Would it be OK if I roughed in the pipes so you could see if they are done correctly and you could tell me if I am doing it properly?"

Sure would, Thad. We'll hang in there as long as we're needed. Have a great weekend. Tom

"Platforming the shower would be the easiest but cutting the cement and installing the trap underground would be the most correct. If you did that you would still have to raise a vent back up the past the wall. With a wall in place could you run the vent to the attic where you could revent back into a existing vent or take it out the roof?"

Are you saying here that I could vent the shower drain into the vent for the sewage pump? I don't think this would be that difficult for me to do.

Pictures:

Showernsink1: This is a picture of the in use sink I was referring to before. As you can see, this sink is not vented but it does work okay. Is there some rule that if you are within a certain distance from the vent in the sewage pump that the trap does not need to be vented? This sink is in the same place I will put a vanity. Should I vent the vanity sink?

Showernsink2: A close up of the works under the sink.

Showernsink3: I spent some time in Home Depot getting various pcv pipes and connectors. This is the arrangement I thought would work best for the shower drain and the drain to the sink in the workroom that would be located almost directly on the opposite side of the wall to the place in the bathroom that will have the shower drain.

As I look at the setup shown in showernsink3, I am more included to try and cut into the concrete floor and bury the trap because it looks too high, so (sorry about this) I have some questions about that...

1. If I do cut around that pipe and dig around it, will I have to cut the cast iron pipe so that it will fit the trap or will the pipe for this (now that it is not held by the concrete) be able to move a little so I can just dig under it and lower it down enough so that the trap will be under the surface of the concrete floor?

2. If the cast Iron pipe has to be cut, how is this done?

3. Once the cast iron pipe is cut, how is the pvc pipe connected to the 2" cut cast iron pipe (now that the iron pipe does not have the female end)?

I took a look down the 2" cast iron pipe with a flashlight and am a bit worried because it appears that the pipe begins a curve almost immediately just after the female head that is sticking out of the concrete floor. What I am saying is that if the pipe IS cut then connecting a curved cast iron pipe to the pcv pipe would be very difficult.

"Are you saying here that I could vent the shower drain into the vent for the sewage pump?"
No! The holding tank vent is different then the house vents and MUST remain a dedicated vent out the roof without any interruptions.

I was assuming that the other sink was vented and not being serviced by a illegal "S" trap when I said you could connect back into the existing lavatory vent.
Question? Do you want this job to go down by the code book or do you just wish to jury-rig it so itworks after a fashion? Your choice. Regards, Tom

I would like to do it the correct way, at least, as much as possible. I could put a vent for the vanity because the wall the vanity will be up against is one that will be sheet rocked. By the way, how long should the pipe be for the AAV vented pipe?

I don't see how the toilet can be vented. Do you think if I don't vent it, that it would cause the flush to be slowed?

I normally go through jobs like this (I have already built an addition onto the house it was a covered porch so it wasn't that hard. The hardest part was to get the permit to do it, and of course, the drywall... which I did have help installing.) with Home depot and Lewds worker help and just common sense but plumbing can be done a million wrong ways and very few right ways, so the help you are giving me is fantastic.

I do have someone who will help me make cuts into the concrete floor, so if you could give me some help there, it would be most appreciated.
Thad

Are you referring to the length of vertical pipe going from the tee upwards (which would normally be the vent pipe)? If you are, don't worry - it doesn't need to be long at all; in fact, you can connect the AAV directly to the top part of the tee (if the design of the AAV makes that possible) without any other piece of pipe whatsoever. The main thing is that the AAV should allow air into the horizontal drain pipe directly below it (like a regular vent), which it can do equally well from 2" or 12" or 120" - not much difference.

If these are the questions that you I-M ed me about I'll address them now.

As I look at the setup shown in showernsink3, I am more included to try and cut into the concrete floor and bury the trap because it looks too high, so (sorry about this) I have some questions about that...

1. "If I do cut around that pipe and dig around it, will I have to cut the cast iron pipe so that it will fit the trap or will the pipe for this (now that it is not held by the concrete) be able to move a little so I can just dig under it and lower it down enough so that the trap will be under the surface of the concrete floor?"

When you open up the cement floor you will find a 2" cast iron quarter bend leaded into a piece of 2" cast iron pipe and turned up with a short piece of 2" piece with a hub. You will then have the option of melting or picking out the lead joint from the hub the quarter bend's connected to and pouring and caulking a cast iron "P" trap back into the hub or cutting off the hub and converting to a PVC "P" trap using a No-Hub Coupling. (See image)

2. If the cast Iron pipe has to be cut, how is this done?

To make a cut when the pipe's in a trench we use a set of cast iron ratchet cutters. You may use the cement saw or a Saws-All, (reciprocating saw) with metal blades. Note; since the cast iron is very hard get plenty of blades and be glad it's not 4" that you have to cut.

3. Once the cast iron pipe is cut, how is the pvc pipe connected to the 2" cut cast iron pipe (now that the iron pipe does not have the female end)?

Thanks again and I believe that I feel confident enough to do the cutting into the cement and dealing with the cast iron pipe now.

The rest of the job, roughing in the bottom of the shower base and tiling it in is covered in a book I got from the library.

There will be a back wall and side wall for the shower area. I would like to keep the other shower stall walls open so that the bathroom does not look so compartmentalized. I was thinking of putting in a frameless glass wall and a glass door but the pricing is very high for these. ( over 9 hundred dollars for one wall and one glass door... sheesh!)... so I am thinking of making an over sized shower curtain that will be most of the time out of the way. Do you have any thoughts on this?

Next, I would like to install an exhaust fan on the ceiling of the bathroom that leads out towards the front of the house. This means that I will have to go through red brick. Do you know what type of tubing or piping is used to make the channel from the bathroom to the outside?

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